Run the following command to generate and compile your parser, and then run all the provided tests:
mvn clean package
java -cp "chocopy-ref.jar:target/assignment.jar" chocopy.ChocoPy --pa1 chocopy.pa1.StudentParser --dir src/test/data/pa1/sample/ --test
In the starter code, only one test should pass. Your objective is to build a parser that passes all the provided tests and meets the assignment specifications.
To manually observe the output of your parser when run on a given input ChocoPy program, run the following command (replace the last argument to change the input file):
java -cp "chocopy-ref.jar:target/assignment.jar" chocopy.ChocoPy --pa1 chocopy.pa1.StudentParser --in src/test/data/pa1/sample/expr_plus.py
You can check the output produced by the staff-provided reference implementation on the same input file, as follows:
java -cp "chocopy-ref.jar:target/assignment.jar" chocopy.ChocoPy --pa1 chocopy.reference.RefParser --in src/test/data/pa1/sample/expr_plus.py
See PA1.pdf for a detailed specification of the assignment.
Refer to chocopy_language_reference.pdf for specifications on the ChocoPy language.
Add the upstream repository remotes (you only need to do this once in your local clone):
git remote add upstream https://github.com/cs164fall2018/pa1-chocopy-parser.git
To sync with updates upstream:
git pull upstream master
Team member 1: Dean Li
Team member 2: Jireh Chew
To properly keep track of INDENT and DEDENT tokens, we entered a special INDENT-handling mode in the lexer. In this mode, we only recognize spaces and tabs, which we pass into a java function to keep track of the current indentation level.
When we encounter a non-whitespace character, we either push it back and start emitting INDENT/DEDENT tokens, or we push it back and re-enter normal processing mode. This ensures we can cycle and emit as many DEDENT tokens as necessary.
To keep track of the actual details, a simple stack is used, as described in project spec.
The hardest language feature was the elif statement expanding into an if else statement. There was nothing technically difficult about this, but it was hard to mentally keep track of what the expanded form is, and to wrap our heads around it.
Our parser detects simple errors in situations where lists of symbols appear. Upon encountering an incorrect element in the list, it simply captures the error, skipping over that symbol, and recovers and continues forward.
For example, in bad.py, we have 3 erroneous statements. Our parser outputs 3 error tokens, showing that it recovered from the error and continue to parse, hence showing the multiple errors.
We used five slip hours. We still have ninety-five slip hours.